Filter



Feb. 11, 1964 A. GUTTAG 3,120,849

FILTER Original Filed Oct. 17. 1961 TNVENTOR /74 w/v G'u r rm;

ATTORNEYS United States Patent 3,120,849 FILTER Alvin Guttag, Bethesda, Md, assignor, by mesne assignments, to Union Qarhide fiorporation, a corporation of New York Uriginal application Oct. 17, 1961, $21. No. 145,575. Divided and this application Nov. 27, 1962, Ser. No.

9 Claims. (Cl. 131-40) This invention relates to tobacco filters and to novel phosphites and polyurethanes.

It is an object of the present invention to prepare tobacco filters from foamed polymers.

Another object is to enhance the fiame resistance of polyurethane filters for tobacco.

A further object is to make novel phosphorus esters of phenol-aldehyde reaction products.

An additional object is to make novel phosphite esters of phenol-aldehyde resins.

A still further object is to prepare novel phosphates and thiophosphates of phenol-aldehyde reaction products.

Yet another object is to prepare novel polymers from phosphorus containing phenol-aldehyde resins.

An additional object is to prepare polyurethanes having improved fire and flame resistance.

A still further object is to prepare foamed polyurethanes from phenol-aldehyde reaction products, e.g., phenolaldehyde resins, having phosphorus containing groupings.

Still further objects and the entire scope of applicability of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications Within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

This application is a continuation-inpart of application Serial No. 124,019, filed July 14, 1961. The entire disclosure of the patent application is hereby incorporated. The instant application is also a division of application Serial No. 145,575, filed October 17, 1961.

Various filters for tobacco smoke have been proposed in the past. Thus, it has been proposed to employ polyurethane cellular plastics as tobacco smoke filters, Winkler Patent 2,770,241. Such polyurethanes and particularly polyurethanes prepared from polyethers have unsatisfactory flame resistance. It has now been found that by employing a phosphorus containing organic reactant as one of the components for preparing the polyurethane that the flame resistance of the filter is greatly enhanced. Polyurethanes prepared from polyethers which previously were unsuited for use as filters can be employed satisfactorily as a result of th present invention. The phosphorus substituent also stabilizes the polyurethane.

In the accompanying drawings which illustrate the invention.

FIGURE 1 is a partially broken away perspective view of a cigarette having a filter according to the invention;

FIGURE 2 is an elevaton, partially broken away and in section of a different embodiment of the invention utilizing a cigarette;

FIGURE 3 is a view in elevation, partially broken away and in section, of a smoking pipe embodying the present invention; and

FIGURE 4 is an enlarged section of a portion of the filter of FIGURE 3.

Referring more specifically to FIGURE 1 there is provided a cigarette designated generally at 8 comprising tobacco 2 and foamed polyurethane filter 4 (e.g., the foamed reaction product of tris (dipropylene glycol) 3,120,849 Fatentecl Feb. 11, 1964 phosphite and toluene diisocyanate), encased in an overall outer paper Wrapper 6.

As shown in FIGURE 2 a cigarette 10 has tobacco 12 encased in paper wrapper 14- and foamed phosphorus containing polyurethane filter 16. In this embodiment of the invention the paper does not encase the filter. Instead the filter has a skin 18 of unfoamed polyurethane. The skin can be formed during the foaming of the polyurethane in conventional fashion. The unfoamed skin prevents the escape of smoke from the sides of the filter when the cigarette is smoked. The skin 18 can be united to the paper wrapper 14 with an adhesive. More preferably the skin is heated briefly to soften it sufiiciently that it will adhere directly to the paper. Instead of the unfoamed polyurethane skin extending slightly beyond the foamed polyurethane and being external to the wrapper at the union, the paper can extend slightly beyond the tobacco and be external to the unfoamed polyurethane skin at the union.

FIGURE 3 shows a smoking pipe 20 having a filter 22 of foamed polyurethane. The foamed polyurethane has particles 24 of cation exchange resin and anion exchange resin dispersed therethrough to assist in the removal of objectionable matter, e.g., carcinogenic compounds, nicotine and the like, from the smoke. While either cation exchange resins or anion exchange resins can be used alone, preferably both types of resins are employed together. To insure thorough dispersal of the ion exchange resins through the foamed polyurethane the ion exchange material is mixed with at least one of the polyurethane forming materials, e.g., with the tris-(dipropylene glycol) phosphite prior to foaming. As a result in the foaming operation the ion exchange material becomes thoroughly dispersed throughout the foamed polyurethane.

As ion exchange resins there can be employed cation exchange resins containing phenolic, carboxyl, sulfonic or phosphonic acid groups.

The cation exchange resin can be in either the free acid or salt form, e.g., in the form of the: sodium salt. Examples of such resins include sulfonated styrenedivinylbenzene copolymer (available commercially as Dowex 50 and Amberlite IR-120) and the other sulfonated resins shown in DAlelio Patent 2,366,007, sulfonated phenolformaldahyde resin, methacrylic acid-ethylene glycol methacrylate copolymer; acrylic acid-ethylene glycolvinylacetate copolymer and the carboxylic acid resins disclosed in DAlelio Patent 2,340,111, styrene phosphonic acid-divinylbenzene copolymer and other copolymers of an alkenylaryl phosphonic acid and a cross linking agent containing at least two ethylenically or acetylenic unsaturated bonds, e.g., having at least two vinylidene groups.

As the anion-exchange resin there can be used phenolpolyalkylene polyamine-forrnaldehyde resins, e.g., phenol-tetraethylenepentarnine formaldehyde resin, quaternary ammonium compounds prepared by reacting a tertiary amine with a haloalkylated crosslink-ed copolymer of a monovinyl hydrocarbon and a polyvinyl hydrocarbon, e.g., the reaction product of trimethylamine with a chloromethylated, cross-linked copolymer of 92% styrene and 8% divinylbenzene (Ambertile IRA-400), or the reaction product of triethylenetetramine with chloromethylated copolymer of 92% styrene and 8% divinylbenzene (Ambertile IR). There can be used any of the cation or anion exchange resins disclosed in Blank US. Patent 2,800,908 or Eirich Patent 2,739,598 or in any of the patents referred to in Blank or cited against Eirich.

The ion exchange resins of course should be of small particle size, e.g., mesh or smaller (Tyler sieve series).

The foamed polyurethanes can be made as either open or closed cell foams. While for many uses closed cell foams are preferred, in the case of cigarette filters there normally are employed open cell foams.

There can be employed conventional polyurethanes made from the reaction product of an organic polyisocyanate and polyol containing polyesters or polyethers providing at least a portion of the polyol reactants has phosphorus in the molecule.

Thus there can be used polyurethanes from toluene diisocyanate and polyol compounds such as polyesters, e.g., ethylene glycol propylene glycol adipate resin (molecular weight 1900), polyethylene glycol adipate phthalate, polyneopentylene sebacate, the reaction product of 1,4-butanediol with adipic acid and a small amount of trimethylol propane, polyethers, e.g., polypropylene glycol molecular weight 1075, LG-168 (glycerine-propylene oxide adduct molecular weight 1000), 1,2,6-hexanetriol-propylene oxide adduct molecular weight 1500 and LK-380 (hydroxyl No. about 372 and being a mixture of 1,1,3-tris [p(hydroxypropoxy) phenyl]propane and glycerine-propylene oxide adduct molecular weight about 265). In place of toluene diisocyanate there can be used any of the other polyisocyanates mentioned hereinafter.

In addition to the polyol set forth above there should be at least 5% and preferably 15% to 85% by weight of the total polyol of a phosphorus containing polyol. There can be used 100% of phosphorus containing polyols. Examples of suitable phosphorus containing poly- 01s for use alone or in admixture With other polyols are given below.

As suitable phosphorus containing polyurethanes mention is made of the reaction products of toluene diisocyanate and tris (dipropylene glycol) phosphite, tris (polypropylene glycol molecular weight 2025) phosphite, dipropylene glycol tetrol diphosphite and the other phosphites set forth hereinafter. There can also be used phosphonates such as his dipropylene glycol hydroxypropoxypropane phosphonate. In place of toluene diisocyanate there can be used any of the other polyisocyanates set forth below.

Frequently, as stated above, there is employed a mixture of 5-85% of phosphorus polyol containing reactant and another polyol for reaction with the polyisocyanate. The phosphorus containing polyol in such event is employed in an amount suflicient to enhance the flame resistance of the polyurethane. While phosphates and thiophosphates can be employed, it is preferred to employ phosphites or phosphonates.

The polyurethanes can be either of the rigid or flexible type and preferably have a density of 2.5 lb./ cu. ft. or less although the density can be as high as 6.5 lb./cu. ft.

Another aspect of the present invention is the preparation of novel phosphorus containing polyols and the formation of polyurethanes from such polyols. The novel phosphorus containing polyols can be used in mak ing tobacco filters.

Thus oxyalkylatecl phenol-aldehyde, phenol-ketone, and phenol-ketone-aldehyde reaction products, e.g., oxyalkylated phenol-aldehyde polymers can be transesterified with a tris hydrocarbon phosphite or tris haloaryl phosphite to form a phosphite containing product. One, two or three phenol or alcohol groups can be removed from the tris substituted phosphite during the transesterification, Preferably, all three groups are removed since the resulting compounds are more stable. The phosphites obtained during this transesterification can be used as stabilizers for vinyl chloride resins, e.g., in an amount of 1%, as stabilizers for polyalkaline glycols, e.g., dipropylene glycol, diethylene glycol, polypropylene glycol 2025, antioxidants for natural rubber and synthetic rubber, e.g., butadiene-styrene copolymer, or as stabilizers for polyethylene and polypropylene.

The phosphite containing oxyalkylated phenol-aldehyde resins can be converted to the corresponding phos- 4 phates by oxidation, e.g., with hydrogen peroxide, and can be converted to the corresponding thiophosphates by treatment with sulfur. The phosphates and thiophosphates are useful as plasticizers for synthetic resins, e.g., polyurethanes and vinyl chloride resins.

The phosphites are easier to make and are more stable than the phosphates and thiophosphates and hence are preferred.

The phosphites, phosphates and thiophosphates of the present invention are particularly useful for incorporation into urethane systems Where they react with the isocyanate groups in the growing polymer chain and thus become fixed. They can be the sole hydroxyl reactant present or they can be used in admixture with other polyhydroxy compounds in forming the polyurethanes. Foamed polyurethanes can be obtained by adding water prior to or simultaneously with the addition of the polyisocyanate. Alternatively, there can be uniformly distributed a liquefied halogen substituted alkane containing at least one fluorine in its molecule in liquid form, having a boiling point at one atmosphere pressure not higher than F. and preferably not lower than -60 F. in either the phosphorus containing polymer reactant or the polyisocyanate reactant and then mixing the reactants and permitting the temperature of the mixture to rise during the ensuing reaction above the boiling point of the liquefied gas to produce a porous polyurethane. Such fluorine containing compounds include dichlorodifluoromethane, dichloromonofluoromethane, chlorodifluoromethane, dichlorotetrafluoroethane. The foams can be formed with such fluorine containing compounds in the manner described in General Tire British Patent 821,342.

Foamed polyurethanes can be made by either the one shot or two step procedure.

The polyurethanes prepared according to the present invention are solids. They have good flame-proofing properties and in the foamed form are useful as linings for textiles, e.g., coats, insulation in building construction, upholstery filling material, pillows, tobacco filters, etc. The unfoamed polyurethane products are useful wherever elastomeric polyurethanes can be employed with the advantage of improved flame and fire resistance. The elastomers can be cured in an oven, e.g., at C. the elastomers in thread form can be employed in making girdles, etc.

As examples of polyisocyanates which can be employed to make the polyurethane there can be used toluene-2,4-diisocyanate; toluene-2,6-diisocyanate; 4-methoxy1,3-phenylene-diisocyanate; 4-chloro1,3 phenylene-diisocyanate; 4-isopropyl-1,3-phenylene diisocyanate; 4-eth0xy-1,3-phenylene-diisocy-anate; 2,4-diisocyanatodiphenylether; 3,3-dimethyl-4,4-diisocyanatodiphenylmethane, mesitylene diisocyanate; durylene diisocyanate; 4,4'-methylenebis (phenylisocyan-ate), benzidine diisocyanate, 0-lit10b6I1Zldine 'd-iisocyanate; 4,4-diisocyanatodibenzyl; 1,5-napl1thalenediisocyanate; tetramethylene diisocyanate, 3,3-bitolylene-4,4'-diisocy'anate, hexamethylene diisocyanate, decamethylene diisocyanate, tritolylmethane triisocyanate, the reaction product of toluene diisocyanate with trimethylolpropane at an NCO/OH ratio of 2:1 (Mondur CB), the reaction product of toluene diisocyanate with a polyol phosphite at an NCO/OH ratio of 2:1, e.g., when the polyol phosphite is dipropylene glycol tetrol diphosphite or tris (pentaerythritolpolypropylene glycol ether) phosphite.

Alternatively as the polyisocyanate there can be used prepolymers made by reacting one or more of the above po lyisocyanates with a polyhydroxy compound such as a polyester having terminal hydroxyl groups, a polyhydric alcohol, hydroxy containing glycerides, etc. The p-repolymers should have terminal isocyanato groups. To insure this it is frequently desirable to employ an excess of 5% or more of the polyisocyanate in forming the prepolymer.

Typical examples of such prepolyrners having isocyanate end groups are those formed from toluene diisocyanate and polyhydroxy compounds. In the illustrative examples a mixture of 80% 2,4-iso1ner and 20% 2,6-isomer of toluene diisoc anate was employed to make the prepolymer. Thus, there can be used the prepolymers from toluene diisocyana'te and castor oil, toluene diisocyanate and blown tung oil (or blown linseed oil or blown soyabean oil), toluene diisocyanate and the polyester of ethylene glycol, propylene glycol and adipic acid having a molecular Weight of 1900 described in example I of Kohrn Patent 2,953,839, as Well as the isooyanate terminated prepolymers in Examples H VIII, inclusive, of the Kohrn patent, toluene diisocyanate and polytetramethylene glycol (1000 molecular Weight), toluene diisocyanate and polypropylene glycol (molecular weight 2025), toluene diisocyanate and dipropylene glycol, toluene diisocyanate and polypropylene glycol (molecular weight 1025), toluene disocyanate and LG56 (glycerine propylene oxide adduct having a molecular weight of 3000), toluene cliisocyanate and 1,2,6-hexanetriol-propyle-ne oxide adducts having molecular weights of 500, 700, 1500, 2500, 3000 and 4000, hexarnethylene diisocyanate and pentaerythritol, toluene diisocyanate and polyethylene sebacate, toluene diisocyanate and a mixture of 98% polypropylene glycol (molecular Weight 1900) with 2% 1,2,6'-hexanetriol, toluene diisocyanate and a copolymer of ethylene oxide and propylene oxide having a molecula Weight of 2020, toluene :disocyanate and glyceryl adipate phthalate polymer, toluene diisocyanate and a mixture of polypropylene ether glycol molecular weight 995 and castor oil described in Example 2 of Kane, US. Patent 2,955,091 as well as the other prepolymers set forth in Examples 1 and 3-11 of Kane, toluene diisocyanate and polypropylene ether glycol (molecular weight 1800) of Example I of Swart Patent 2,915,496 and the prepolymers of Examples I I, III, VI and VIII of the Swart patent, toluene diisocyanate and tris (dipropylene glycol) phosphite and toluene diisocyanate and tris (polypropylene glycol 2025) phosphite.

Any of the conventional basic catalysts employed in polyurethane foam technology can be used. These in clude N-methyl morpholine, N-ethyl morpholine, trimethylamine, triethylarnine, tributylemine and other tri alkylamines, S-diethylaminopropionamide, heat activated catalysts such as triethylamine citrate, 3-morpholinopropion amide, Z-diethylaminoacetamide, the esterification product of 1 mole of adipic acid and 2 moles of diethylethanolamine, 3-diethylaminopropionamide, diethylethanolamine, triethylenediamine, l l,l l,N',l l'-tetr-akis (2hydroxypropyl) ethylenediamine (Quedrol), N,N-dimethylpiperazine, N,N-dimethylhexahydroaniline, tribenzyl amine and sodium phenolate.

There can also be used tin compounds, e.g., dibutyl't-in dilaurate, dibutyltin diacetate, di-2-ethylhexyltin oxide, dibutyltin monolaurate, octylstannoic acid, dibutyltin diethoxide, dibutyltin dioctoa-te, tributyltin monolaurate, dimethyltin diacetate, dioctyltin diacetate, dilauryltin diacetate, dibutyltin maleate and other hydrocarbontin acylates, dibutyltin dimet-hoxide and other hydrocarbcntin alkoxides, trimethyltin hydroxide, trimethyltin chloride, triphenyltin hydride, triallyltin chloride, tributyltin fluoride, dibutylt-in dibromide, bis (carboethoxyrnethyl) tin diiodide, tributyltin chloride, trioctyltin acetate, butyltin trichloride, octyltin tris (thiobutoxide), dimethyltin oxide, dipheny-ltin oxide, stannous octanoate, stannous oleate, as well as the other tin compounds set forth in Hostettler French Patent 1,212,252.

Conventional surfactants can be added in an amount of 1% or less, e.g., 0.2% by weight of the composition. The preferred surfactants are silicones, e.g., polydimethyl siloxane having a viscosity of 3 to 100 centistokes, such as polydimethyl siloxane (50 centistokes grade); triethoxy dimet-hyl polysiloxane molecular weight 850 copolymerized with a dimethoxypolyethylene glycol having a molecular Weight of 750 and any of the other siloxanes disclosed in Hostettler French Patent 1,212,252.

The novel hydroxy containing phosphites, phosphates and thiophosphates can be used as the sole hydroxyl group containing compounds in forming the polyurethanes or they can be replaced in part by other polyhydroxy containing compounds such as polyethylene glycol having molecular weights of 400 to 3000, polypropylene glycol having molecular weights of 400 to 3000, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,4-butanediol, thiodiglycol, glycerol, trimethyoloethane, trimethylolpropane, glycerine-propylene oxide adduct, 1,2,6- hexanetriol-propylene oxide adducts having molecular weights of 500, 700, 1500, 2500, 3000 or 4000, trimeth ololphenol, triethanolamine, pentaerythritol, methyl glucoside, castor oil, glycerine ethylene oxide adducts, diethanolamine, ether triols from glycerine and propylene oxide having molecular weights of 265, 1000 and 3000 (available commercially as LG633, LG-163 and LG56, respectively), sorbitol-propylene oxide adduct having a molecular Weight of 1000, pentaerythritol-propylene oxide adducts molecular weights 368 and 1000, oxypropylated sucrose, blown linseed oil, blown soyabean oil, Quadrol, mixed ethylene glycol-propylene glycol adipate resin (molecular weight 1900), polyethylene adipate phthalate, polyneopentylene sebacate, tris (dipropylene glycol) phosphite, tris (polypropylene glycol 2025) phosphite, dipropylene glycol tetrol diphosphite, tripropylene glycol hexol tetraphosphite, tris (pentaerythritol-polypropylene glycol ether) phosphite (molecular weight about 3000), 1-2,6- hexanetriolpropylene oxide adduct molecular weight 750 (LHT 240) hexol phosphite, and the product made by reacting an excess of 1,4-butanediol with adipic acid and including a small amount of uimethylolpropane for each 3000 to 12,000 molecular weight units of polyester.

While the polytu'ethanes produced in general are solids, the phosphites, phosphates and thiophosphates from which they are made are normally liquids.

As the oxyalkylated phenol-aldehyde and/or ketone condensation products, there can be employed the organic reaction products of (A) an alpha-beta alkylene oxide having 2 to 4 carbon atoms from the group consisting of ethylene oxide, propylene oxide, butylene oxide, glycide and methyl glycide with (B) an oxyalkylation susceptible fusible phenol-aldehyde and/ or ketone condensation product. The oxyalltylated phenohaldehyde and/or ketone condensation products, e.g., resins, are characterized by introduction into the molecule at the phenolic hydroxyl groups of a plurality of divalent radicals having the formula (R 0) in which R is a member of the class of ethylene, propylene (methylethylene), butylene (ethylethylene), hydroxypropylene and hydroxybutylene radicals and n is a member varying from 1 to 20; with the proviso that an average of at least 2 moles of alkylene oxide is introduced into the phenol-aldehyde (and/or ketone) condensation product. Preferably at least one R 0 radical is introduced for each available phenolic hydroxyl.

The most preferred alkylene oxide is propylene oxide and next to propylene oxide it is preferred to use ethylene oxide.

As starting phenol-aldehyde and/or ketone condensation products there can be used any of the phenol-a1dehyde and/ or ketone resins disclosed in De Groote Patent 2,499,365. As the oxyalkylated phenolaldehyde and/or ketone condensation product there can be employed any of the oxyalkylated phenol-aldehyde and/ or ketone resins of De Groote. The entire disclosure of the De Groote patent is hereby incorporated by reference. There can also be used as starting products phenol-ketone condensation products and mixed phenol-ketone-aldehyde condensation products, e.g., of the types set forth in De Groote. The condensation products of the present invention have at least 3 phenolic units and at least two aldehyde and/ or ketone residues or units. Particularly pertinent portions of De Groote are column 5, lines 48-68, Example 1a 188a, inclusive, Examples 203a-211a, inclusive, Examples 258a-339a, inclusive, column 91, line 72, to column 92, line 17, column 92, lines 55-72, column 93, line 9 to column 95, line 23, column 97, line 14, to column 99, line 72, Examples 1b-19b, inclusive, Examples 24b-26b, inclusive, Example 43b, Examples 4817-6112, inclusive, Example 66b, Example 74b, column 124, line 53, to column 125, line 17, column 125, line 39, to column 126, line 39 and all of the tables showing oxyalkylatio-n on columns 125-130, inclusive, the tables on columns 131-136, inclusive, except for those portions referring to Examples 200a, 201a, 202a, 195a, 196a, 197a, 213a, 239a, 257a, 351a and 344a through 376a.

Thus, any of the oxyalkylated phenolaldehyde and/ or ketone resins of De Groote can be employed as starting materials in the present invention. Preferably, the resin employed has a hydrocarbon or halogen substituent in the ortho or para position to the phenolic hydroxyl, most preferably in the para position. However, as indicated, trifunctional or higher functional phenols can be employed. When using phenol per se or meta cresol, for example, novolaks can be used. Alternatively, resoles can be employed providing the phenol-formaldehyde resin, for example, has not reached the infusible stage.

As examples of phenols which can be used mention is made of phenol, rn-cresol, o-cresol, p-cresol, o-chlorophenol, p-chlorophenol, rn-chlorophenol, p-bromophenol, p-fluorophenol, p-ethylphenol, p-butylphenol, p-tertiary butylpheno l, p-phenylphenol, o-tertiary butylphenol, psecondary butylphenol, p-tertiaiy amylphenol, p-secondary amylphenol, p-cyclohexylpheuol, resorcinol, 3,4- xylenol, bisphenol A, o-tertiary amylphenol, p-tertiary hexylphenol, p-octylphenol, p-styrylphenol, cresylic acid, p-nonylphenol, p-dodecylphenol, o-dodecylphenol, p-nonylphenol, p-rnethylphenol, p-decylphenol, p-curnylphenol, p-octadecylphenol, p-eicosanylphenol, p-tetraicosanylphenol, p-isopropylphenol, o-isopropylphenol, thymol, carvacrol, alpha-naphthol, beta-naphthol, hydroquinone and cardanol. As the aldheyde or ketone there can be used formaldehyde, furfural, acetaldehyde, propionaldehyde, butyraldehyde, benzaldehyde, heptaldehyde, acrolein, glyoxal, 2-ethyl-3 propyl acrolein, acetone, methyl ethyl ketone, cyclohexanone and cldoroacetone.

Preferably, the phenol has an alkyl substituent of 1 to 24 carbon atoms in the para position or in the ortho position. The preferred aldehyde is formaldehyde. Preferably, the resins have 3 to 7 phenolic nuclei with an average of 4.5 to 5.5 nuclei. However, the resins can have 15 or even more structural units (as shown on column 99 of the De Groote patent).

While De Groote indicates that its oxyalkylated products should be hydrophyllic this is not an essential feature of the present invention since products which are still hydrophobic can be employed.

As previously stated there should be used at least two moles of alkylene oxide per mole of phenol-aldehyde (and/or ketone) condensation product and preferably at least one R radical is introduced per each available phenolic hydroxyl. Most preferably at least two moles of alkylene oxide (or hydroxyalkylene oxide) are used per structural unit of the phenol-aldehyde or phenol-ketone resin. There can be used more of the alkylene oxide, e.g., 6 to 1; 10 to 1; to 1 or to 1 moles per structural unit of the resin. For use in forming flexible foamed polyurethanes desirably at least 6 moles of alkylene oxide, preferably propylene oxide are used per structural unit. For making rigid foamed polyurethanes it is frequently desirable to reduce the alkylene oxide to 1 to 2 moles per structural unit in order to get a maximum of flame resistance.

For the transesteri-fication of the oxyalkylated phenolaldehyde and/ or ketone resin there can be used trihydrocarbon or trihaloaryl phosphites including triallcyl and triaryl phosphites such as triphenyl phosphite, tri-o-cresyl phosphite, tri-m-cresyl phosphite, tri-p-cresyl phosphite, tri-xylenyl phosphite, tridecyl phosphite, diphenyl decyl phosphite and triethyl phosphite as Well as tri-haloaryl phosphites such as tri-p-chlorophenyl phosphite, tri-ochlorophenyl phosphite, etc.

Preferably, the reaction between the oxylalkylated phenol-aldehyde resin and the tri-hydrocarbon phosphite is catalyzed by a dihydrocarbon (e.g., aryl or alkyl) or dihaloaryl phosphite, e.g., 0.11% of diphenyl phosphite, di-o-cresvl phosphite, di-p-cresyl phosphite, dimethyl phosphite, diethyl phosphite, didecyl phosphite, dioctadecyl phosphite, di-p-chlorophenyl phosphite, etc. Such catalysts are neutral and are particularly advantageous with therinosetting resins since alkaline catalysts tend to advance the resin.

Alkaline catalysts can be employed for the transesterifioation. Such catalysts preferably have a pH of at least 11 in a 0.1 N solution. Examples of these catalysts are sodium phenolate, sodium cresylate, sodium methylate, potassium phenolate and sodium decylate. They are employed in an amount of 0.1-l% of the reactants.

By utilizing an excess of the oxyalkylated phenoltaldehyde or ketone resin, e.g., a five fold excess, calculated on the molar ratio of the resin structural unit molecular weight to the triaryl phosphite molecular weight there can be obtained products wherein 3 different resinmolecules are attached to a single phosphorous atom. As the amount of resin is reduced, the tendency for different hydroxyl groups on the same resin molecules reacting with a single phosphorus atom is increased. When an excess of starting oxylalkylated resin is employed to form the phosphite it can be left in the phosphite product and utilized as a polyol in forming the polyurethane.

To determine the amount of isocyanate to employ, a sample of the hydroxyal'kylated resin phosphite (with or without hydroxyalkylated resin) is tested to determine its hydroxyl number and then the polyisocyanate is added in conventional manner.

Unless otherwise indicated, all parts and percentages are by weight.

In preparing urethane foams according to the invention a rigid foam is made by utilizing a hydroxyl compound or mixture of hydroxyl compounds having a hydroxyl number of 350-750; a semi-rigid foam is prepared if the hydroxyl number is 75-350 and a flexible foam is prepared if the hydroxyl number is 35-75.

In general, the higher the alkyl group the lower the hydroxyl number. Also, the lower the molecular weight of the alkylene oxide the higher the hydroxyl number (providing there is not an extra hydroxyl group on the alkylene oxide). In preparing urethane foams (and other urethane polymers) the following values are of interest.

No.0f H drox lNumher Resin Units y y 111 Resin 15E 3E 3P 151 GP 10E 10F 20? Phen0l formaldehyde"... 5 190 160 46 82 65 35 Do 7 170 106 Cresolformaldehyde"-.. 5 178 153 64 Do 7 163 103 Butylphenolformaldehyde..- 5 55 150 134 43 88 T4 60 34 Do 7 1. 143 94 65 Amylphenolformaldehyde..." 5 122 Do 7 91 a... Octylphenolformaldehyde 5 68 56 Do 7 85 Chlorophenolformaldehyde 5 63 In the above table the term 313 signifies three ethylene oxide groups per resin unit, 3P signifies three propyiene oxide groups per resin unit, 6P signifies six propylene oxide groups per resin unit, 10E signifies ten ethylene oxide groups per resin unit, 10P signifies ten propylene oxide groups per resin unit, 15F signifies fifteen propylene oxide groups per resin unit, 15E signifies fifteen ethylene oxide groups per resin unit, and 20F signifies twenty propylene oxide groups per resin unit.

Unless otherwise indicated, in the following examples the oxaylkyl-ated phenol-formaldehyde and/ or ketone resins had about phenol units in the molecule.

Example 1 l 9 Example 6 The process of Example 5 was repeated but the oxypropylated phenol-formaldehyde novolak employed had propylene oxide groups per phenol unit in the resin molecule. There was recovered the tris oxypropylated phenol-formaldehyde novolak phosphite as a viscous liquid after recovery of three moles of phenol.

Example 7 The process of Example 4 was repeated utilizing an oxyethylated phenol-formaldehyde novolak having 10 ethylene oxide groups per phenol unit in the resin molecule.

Example 8 The process of Example 5 was repeated but the oxypropylated phenol-formaldehyde novolak employed had 10 propylene oxide groups per phenol unit in the resin molecule.

where Z is the grouping This formula is representative only and the ester link ages for the phosphorus, for example, might be present on other units of the resin molecule instead.

Example 2 One mole of the oxypropylated p-tertiary butylphenolformaldehyde resin of Example 2b of De Groote (con taining about 8.6 moles of ethylene oxide per phenol unit in the resin molecule) was mixed with one mole of triphenyl phosphite and 2 grams of diphenyl phosphite. The mixture was heated in vacuo (10 mm.) at 120 C. and the phenol formed was distilled and collected until about 3 moles had distilled over. The tris oxypropylated p-tertiary ontylphenol-for1naldehyde resin phosphite formed was a viscous liquid.

Example 3 The process of Example 2 was repeated but distillation was stopped when one mole of phenol had come over. The product was monooxypropylated p-tertiary butylphenol-formaldehyde resin phosphite.

Example 4 The process of Example 1 was repeated using an oxyethylated phenol-formaldehyde novolak having 3 ethylene oxide groups per phenol unit in the resin molecule. There was recovered the tris oxyethylated phenol-tormaldehyde resin phosphite.

Example 5 The process of Example 4 was repeated but there was used an oxypropylated phenol-formaldehyde novolak having 3 propylene oxide groups per phenol unit in the resin molecule. There was recovered the tris oxypropylated phenol-formaldehyde resin phosphite after removal of three moles of phenol by distillation.

Example 9 The process of Example 5 was repeated but the oxypropylated phenol-formaldehyde novolak employed had 20 propylene oxide groups per phenol unit in the resin molecule.

Example 10 One mole of oxypropylated thermosetting phenolformaldehyde resin having 15 propylene oxide groups per phenol unit was mixed with one mole of triphenyl phosphite and 2 grams of didecyl phosphite. The mixture was heated in the vacuo (10 mm.) and three moles of phenol removed by distillation to recover the tris oxypropylated phenol-formaldehyde resin phosphite.

Example 11 One mole of oxypropylated phenol-formaldehyde n0- volak having 7 phenol units in the resin molecule and having 6 propylene oxide groups per phenol unit was mixed with one mole of trioctyl phosphite and 2 grams of dioctyl phosphite. The mixture was heated in vacuo (10 mm.) until three moles of octyl alcohol were removed by distillation to recover the tris oxypropylated phenol-formaldehyde novolak phosphite.

Example 12 One mole of oxypropylated p-cresol-formaldehyde resin having 5 cresol units in the resin molecule and having 3 ethylene oxide groups per cresol unit was mixed with one mole (310 grams) of triphenyl phosphite and 3 grams of diphenyl phosphite. The mixture was heated in vacuo (10 mm.) until three moles of phenol were removed by distillation to recover the tris oxyethylated cresol-formaldehyde resin phosphite.

Example 13 The process of Example 12 was repeated replacing the oxyethylated p-cresol-formaldehyde resin by an oxy propylated o-cresol-formaldehyde resin having 3 propylene oxide units per cresol unit. The product recovered was tris oxypropylated o-cresol-formaldehyde resin phosphite.

Example 14 The process of Example 13 was repeated using oxypropylated p-cresol-formaldehyde resin having 5 cresol units in the resin molecule and having propylene oxide units per cresol unit. The tris oxypropylated o-cresolformaldehyde resin phosphite Was recovered as a substantially colorless viscous liquid.

Example One mole of oxypropylated p-cresol-formaldehyde resin having 7 cresol units in the resin molecule and having 6 propylene oxide groups per cresol unit was mixed with one mole of triphenyl phosphite and 3 grams of diphenyl phosphite. The mixture was heated in vacuo (10 mm.) until about three moles of phenol were removed by distillation to recover the tris oxypropylated p-creso1-form aldehyde resin phosphite.

Example 16 One mole of oxypropylated p-tertiary butylphenolformaldehyde resin having 5 butylphenol units in the resin molecule and having 2 propylene oxide groups per butylphenol unit was mixed with one mole of triphenyl phosphite and 3 grams of diphenyl phosphite. The mixture was heated in vacuo (10 mm.) until about three moles of phenol were removed by distillation to recover the tris oxypropylated p-tertiary butylphenol-formaldehyde resin phosphite.

Example 17 One mole of oxyethylated o-n-butylphenol-formaldehyde resin having 5 butylphenol units in the resin molecule and having 3 ethylene oxide groups per butylphenol unit was mixed with one mole of triphenyl phosphite and 3 grams of dicresyl phosphite. The mixture was heated in vacuo (10 mm.) until three moles of phenol were removed by distillation to recover the tris oxyethylated o-n-butylphenol-fornraldehyde resin phosphite.

Example 18 The process of Example 17 was repeated using oxyethylated p-secondary butylphenol-formaldehyde resin having 15 ethylene oxide groups per butylphenol unit. There was recovered tris oxyethylated p-secondary b utylphenol-formaldehyde resin phosphite as a viscous liquid.

Example 19 One mole of oxypropylated p-tertiary butylphenolformaldehyde resin having 5 butylphenol units in the resin molecule and having 15 propylene oxide groups per butylphenol unit was mixed with one mole of triphenyl phosphite (310 grams) and 2.5 grams of diphenyl phosphite. The mixture was heated in vacuo (10 mm.) until about three moles of phenol were removed by distillation to recover the tris oxypropylated p-tertiary butylphenolformaldehyde resin phosphite as a viscous liquid.

Example 21 The process of Example 20 was repeated but the oxypropylated p-tertiary butylphenol-formaldehyde resin employed had 6 propylene oxide groups per butylphenol unit.

Example 22 One mole of oxypropylated p-tertiary butylphenolformaldehyde resin having 5 butylphenol units in the resin molecule and having 10 propylene oxide groups per butylphenol unit was mixed with one mole of triphenyl phos phite and 3 grams of diphenyl phosphite. The mixture was heated in vacuo (10 mm.) until about three moles (282 grams) of phenol were removed by d-istitllation to recover the tris oxypropylated p-tertiary butylphenolformaldehyde resin phosphite as a colorless viscous liquid.

Example 23 The process of Example 22 was repeated replacing the xypropylated resin by one mole of oxyethylated ptertiary butylphenol-forrnaldehyde resin having 10 ethylene oxide groups per butylphenol unit. The product recovered was tris oxyethylated p-tertiary butylphenolformaldehyde resin phosphite as a liquid.

Example 24 The process of Example 22 was repeated replacing the oxypropylated resin by one mole of oxypropylated ptertia-ry butylphenol-formaldehyde resin having 20 propylene oxide groups per butylphenol unit. The product recovered was tris oxypropylated p-tertiary butyphenolformaldehyde resin phosphite as a colorless liquid.

Example 25 The process of Example 22 was repeated replacing the oxypropylated resin by one mole of oxypropylated p-nbutylphenol-butyraldehyde resin having 10 propylene oxide groups per butylphenol unit. The product recovered was tris oxypropylated p-n-butylphenol-butyraldehyde resin phosphite as a colorless liquid.

Example 26 The process of Example 22 was repeated replacing the oxypropylated resin by one mole of oxypropylated ptertiary butylphenol-furfural resin having 10 propylene oxide groups per butylphenol unit. The product recovered was tris oxypropylated p-tertiary butylphenol-furfural resin phosphite.

Example 27 The process of Example 22 was repeated replacing the oxypropylated resin by one mole of oxypropylated ptertiary butylphenol-formaldehyde resin having 7 butylphenol units in the resin molecule and having 6 propylene oxide groups per butylphenol unit. The product recovered was tris oxypropylated p-tertiary butylphenol-formaldehyde resin phosphite.

Example 27a The process of Example 22 was repeated replacing the oxypropylated resin by one mole of oxypropylated ptertiary butylphenol-formaldehyde resin having 7 butyl phenol units in the resin molecule and having 10 propylene oxide groups per butylphenol unit. The product recovered was tris oxypropylated p-tertiary butylphenolformaldehyde resin phosphite as a liquid.

Example 28 The process of Example 22 was repeated replacing the oxypropylated resin by one mole of oxypropylated ptertiary amylphenol-formaldehyde resin having 5 amylphenol units in the resin molecule and having 3 propylene oxide groups per amylphenol unit. The product recovered was tris oxypropylated p-tertiary amylphenol-formaldehyde resin phosphite.

13 Example 29 The process of Example 28 was repeated but the oxypropylated amylphenol-formaldehyde resin had 10 propylene oxide groups per amylphenol unit. The phosphite product recovered was a viscous liquid.

Example 30 The process of Example 22 was repeated replacing the oxypropylated resin by one mole of oxypropylated ptertiary amylphenol-formaldehyde resin having 7 amylphenol units in the resin molecule and having 6 propylene oxide groups per amylphenol unit. The product recovered was tris oxypropylated p-tertiary amylphenol-formaldehyde resin phosphite.

Example 3] The process of Example 22 was repeated replacing the oxypropylated resin by one mole of oxypropylated octylphenol-formaldehyde resin having octylphenol units in the resin molecule and having 2 propylene oxide groups per octylphenol unit. The product recovered was tris oxypropylated p-octylphenol-formaldehyde resin phosphite.

Example 32 The process of Example 31 was repeated but the oxypropylated p-octylphenol-formaldehyde resin used had propylene oxide groups per octylphenol unit. The tris oxypropylated p-octylphenol-formaldehyde resin phosphite recovered was a viscous liquid.

Example 33 The process of Example 31 was repeated but the oxypropylated poctylphenol-formaldehyde resin used had 3 propylene oxide groups per octylphenol unit.

Example 33a The process of Example 31 was repeated but the starting resin was replaced by oxyethylated p-octylphenolformaldehyde resin having 10 ethylene oxide groups per octylphenol unit. The tris oxyethylated p-octylphenolformaldehyde resin phosphite was a viscous liquid.

Example 34 The process of Example 31 was repeated but the oxypropylated resin employed was oxypropylated p-octylphemoi-formaldehyde resin having 7 octylphenol units and having 6 propylene oxide groups per octylphenol unit.

Example 35 The process of Example 22 was repeated but the starting resin was oxypropylated p-dodecylphenol-formaldehyde resin having 10 propylene oxide groups per dodecylphenol unit. There was recovered tris oxypropylated dodecylphenol-forrnaldehyde resin phosphite as a liquid.

Example 36 The process of Example 22 was repeated but the starting resin was oxypropylated p-chlorophenol-formaldehyde resin having 10 propylene oxide groups per chlorophenol unit. There was recovered tris oxypropylated pchlorophenol-formaldehyde resin phosphite as a liquid.

Example 37 phites, e.g., with hydrogen peroxide (either 30% or 50% concentration) or other peroxy compounds, e.g., peracetic acid. The peroxy compound is used in an amount which is stoichiometrically equivalent to the amount of phosphorus present.

Example 39 To the tris oxypropylated p-tertiary butylphenol-formaldehyde resin phosphite of Example 22 there: was added an equimolecular amount of 50% aqueous hydrogen peroxide. After reaction was complete, the water was distilled off leaving a residue of tris oxypropylated p-tertiary butylphenol-formaldehyde resin phosphate as a liquid.

In place of the phosphite resin of Example 22 in a similar manner there can be converted into phosphates any of the other phosphite resins of Examples 1-21 and 23-38.

Example 40 To the tris oxypropylated p-tertiary butylphenol-forrnaldehyde resin phosphite of Example 22 there was added an equimolecular amount of elemental sulfur. The mix ture was heated to 1l0l30 C. for one hour. The product was tris oxypropylated p-tertiary butylphenolformaldehyde resin thiophosphate as a liquid.

In place of the phosphite resin of Example 22 in a similar manner there can be converted into thiophosphates any of the other phosphite resins of Examples 1-21 and 23-38.

In the following Examples 41-69 a one shot foam was prepared by utilizing the following standard formulation in a 10 ounce cup.

Grams Water 0.37 Dibutyltin dilaurate 0.07 Polydimethyl siloxane 0.12 N-ethyl morpholine 0.1 Polyol As indicated This mixture is designated in the following examples as Formulation A.

Foams were made by adding Formulation A to 5.2 grams of toluene diisocyanate (a mixture of of the 2,4-isomer and 20% of the 2,6-isomer). The foams prepared were placed in a C. curing oven for 20 minutes.

The 80:20 mixture of toluene diisocyanates was used in all of the following examples.

Example 41 The polyol used in Formulation A was 15.4 grams of the tris oxypropylated p-tertiary butylphenol-formaldehyde resin phosphite prepared in Example 22. Upon addition of the 5.2 grams of toluene diisocyanate there was formed a solid polyurethane foam.

Example 42 The polyol used in Formulation A was the same as that in Example 41. The water was omitted from Formulation A and 5.2 grams of the toluene diisocyanate (80:20 ratio of 2,4 and 2,6-isomers) were added. After prepolymer formation was complete, there was added 0.37 gram of water with strong stirring to obtain a solid foamed product.

Example 43 The polyol used in Formulation A was a mixture of 7.7 grams of the polyol used in Example 41 together with 7.2 grams of LG-56. After addition of the 5.2 grams of toluene diisocyanate, there was obtained a nice solid foam.

Example 44 The polyol used in Formulation A was a mixture of 2.1 grams of the tris oxyethylated phenol-formaldehyde resin phosphite of Example 4 and 7 grams of polypropylene glycol 2025. Upon addition of 5.2 grams of toluene diisocyanate a solid foamed polymer was produced.

Example 45 The polyol used in Formulation A was a mixture of 2.5 grams of the tris oxypropylated phenol-formaldehyde resin phosphite of Example 5 and 7.2 grams of LG56. Upon addition of 5 .2 grams of toluene diisocyanate a solid foamed polymer was produced.

Example 46 The polyol used in Formulation A was 17.2 grams of the tris oxypropylated phenol-formaldehyde resin phosphite of Example 6. Upon addition of 5.2 grams of toluene diisocyanate a solid foamed polymer was produced.

A similar foam Was prepared using the phosphite of Example 10.

Example 47 The polyol used in Formulation A was a mixture of 7.3 grams of the tris oxypropylated phenol-formaldehyde res-in phosphite of Example 11 and 7.2 grams of LG56. Upon addition of 5.2 grams of toluene diisocyanate a solid foamed polymer was produced.

Example 48 The polyol used in Formulation A was a mixture of 2.7 grams of the tris oxypropylated cresol-formaldehyde rsein phosphite of Example 13 and 7.2 grams of LG56. Uponaddition of 5.2 grams of toluene diisocyanate a foamed polymer was produced.

Example 49 The polyol used in Formulation A was a mixture of 7 'grams of the tris oxypropylated cresol-formaldehyde resin phosphite of Example 14 and 7 grams of polypropylene glycol 2025. Upon addition of 5.2 :grams of toluene diisocyanate a solid foamed polymer was produced.

Example 50 The polyol used in Formulation A was a mixture of 2.5 grams of the tris oxyethylated bu-tylphenol-formaldehyde resin phosphite of Example 16 and 7.2 grams of LG56. Upon addition of 5.2 grams of toluene diisocyanate a solid foamed polymer was produced.

Example 51 The polyol employed in Formulation A was 14.4 grams of the tris oxyethylated butylpheuol-form'aldehyde resin phosphite of Example 18. Upon addition of 5.2 grams of toluene diisocyanate a solid foamed polymer was produced.

Example 52 The polyol employed in Formulation A was a mixture of 2.7 grams of the tris oxyethylated butylphenol-formaldehyde resin phosphite of Example 17 and 7.2 grams of LG56. Upon addition of 5.2 grams of toluene diisocyanate a solid foamed polymer was produced.

Example 53 The polyol employed in Formulation A was a mixture of 9.3 grams of the tris oxypropylated butylphenol-formaldehyde resin phosphite of Example 20 and 7.2 grams of LG56. Upon addition of 5.2 grams of toluene diisocyanate a solid foamed polymer was produced.

Example 54 The polyol employed in Formulation A was a mixture of 4.5 grams of the tris oxypropylated butylphenol-formaldehyde resin phosphite of Example 21 and 7.2 grams of polypropylene glycol 2025. A solid foam was formed upon addition of 5.2 grams of toluene diisocyanate.

Example 55 The polyol employed in Formulation A was a mixture of 5.5 grams of the tris oxyethylated butylphenol-formal- 16 dehyde resin phosphite of Example 23 and 7.2 grams of LG56. A solid foam was formed upon the addition of 5.2 grams of toluene diisocyanate.

Example 56 The polyol employed in Formulation A was a mixture of 12 grams of the tris oxypropylated butylphenol-formaldehyde resin phosphite of Example 24 and 7.2 grams of LG56. The foam was produced upon the addition of 5 .2 grams of toluene diisocyanate.

Example 57 The polyol employed in Formulation A was a mixture of 5.7 grams of the tris oxyethylated butylphenol-formaldehyde resin phosphite of Example 1 and 7.2 grams of polypropylene glycol 2025 The foam was produced upon the addition of 5 .2 grams of toluene diisocyanate.

Example 58 The polyol employed in Formulation A was a mixture of 5.7 grams of the tris oxypropylated butylphenol-formaldehyde resin phosphite of Example 2 and 7.2 grams of LG-56. The solid foam was produced upon the addition of 5.2 grams of toluene diisocyanate.

Example 59 The polyol employed in Formulation A was a mixture of 3.8 grams of the tris oxypropylated butylphenol-for-maldehyde resin phosphite of Example 27 and 7.2 grams of LG56. A solid foam was produced upon the addition of 5.2 grams of toluene diisocyanate.

Example 60 The polyol employed in Formulation A was a mixture of 6 grams of the tris oxypropylated butylpheno'l-formaldehyde resin phosphite of Example 27 and 7.2 grams of LGS 6. A solid foam was produced upon the addition of 5.2 grams of toluene diisocyanate.

Example 61 The polyol employed in formulation A was 13.8 grams of the tris oxypropylated butylphenol butyraldehyde resin phosphite of Example 25. A solid foam was formed upon the addition of 5 .2 grams of toluene diisocyanate.

Example 62 The polyol employed in Formulation A was 14.4 grams of the tris oxypropylated butylphenol-furfural resin phoshpite of Example 26. A solid foam was formed upon the addition of 5.2 :grams of toluene diisocyanate.

Example 63 The polyol employed in Formulation A was 14.4 grams of the tris oxypropylated amy-lphenol-formaldehyde resin phosphite of Example 29. A solid foam was formed upon the addition of 5 .2 grams of toluene diisocyanate.

Example 64 The polyol employed was a mixture of 6 grams of the tris oxyethylated octylphenol-formaldehyde resin phosphite of Example 33a and 7.2 grams of LG56. A solid foam was formed upon the addition of 5 .2 grams of toluene diisocyanate.

Example 66 The polyol employed was 14.4 grams of the tris oxypropylated octylphenol-formaldehyde resin phosphite of Example 32. A solid foam was formed upon the addition of 5.2 grams of toluene diisocyanatc.

1? Example 66a The polyol employed was a mixture of 6.5 grams of the tris oxypropylated chlorophenol-formaldehyde resin phosphite of Example 36 and 7.2 grams of LG56. Upon the addition of 5.2 grams of toluene diisocyanate a solid foam was produced.

Example 67 The polyol employed was 14.4 grams of the tris oxypropylated dodecylphenol-formaldehyde resin phosphite of Example 35. Upon the addition of 5.2 grams of toluene diisocyanate a solid foam was produced.

Example 68 The polyol employed was a mixture of 2.9 grams of the tris oxypropylated nonylphenol-formaldehyde resin phosphite of Example 38 and 7.2 grams of LG56. Upon the addition of 5.2 grams of toluene diisocyanate a solid foam was produced.

Example 69 The polyol employed was 14.4 grams of the tris oxypropylated butylphenol-formaldehyde resin phosphate of Example 39. Upon the addition of 5.2 grams of toluene diisocyanate a solid foam was produced.

Example 70 The polyol employed was 14.4 grams of the tris oxypropylated butylphenol-formaldehyde resin thiophosphate of Example 40. Upon the addition of 5.2 grams of toluene diisocyantne a solid foam was produced.

Example 71 237 grams (0.021 mole) of the tris oxypropylated butylphenohformaldehyde resin phosphite of Example 22 and 95 grams (0.55 mole) of toluene diisocyanate were heated together at 90 C. for one hour and dissolved in 400 ml. of dimethyl formamide solvent and portions were painted on (a) a glass dish, ([2) a steel plate and (c) a piece of Wood. The samples were placed in an oven at 120 C. for one hour to remove the solvent and then air cured for 4 hours. In all cases a clear resin coating was obtained. The coating acted as a fire retardant. The polyurethane formed was useful therefore as a nonburning paint.

Example 72 was Example 73 The process of Example 1 was repeated utilizing the resin of De Groote Example 327a which had been etherified with 250 grams of propylene oxide per 167 grams of resin. One mole of the oxypropylated resin Was used with one mole of triphenyl phosphite and 3 grams of diphenyl phosphite.

Example 74 The process of Example 1 was repeated utilizing the resin of Example 317a of De Groote which had been further reacted with 3 moles of propylene oxide per phenolic hydroxyl group.

Example 75 The polyol used in Formulation A was a mixture of 7.2 grams of LG-5 6 and 2.5 grams of tris oxypropylated phenol-formaldehyde novolak phosphite having 5 phenolic groups and having 1 propylene oxide unit for each phenolic group and having a hydroxyl number of about i8 190. The oxypropylated novolak phosphite included some free oxypropylated novolak as a result of incomplete esteri'iication. Upon addition of 5.2 grams of toluene diisocyanate a solid foamed polymer was produccd.

The phosphites prepared in Examples 72, 73 and 74 can be similarly converted into foamed polyurethanes by replacing the tris oxypropylated phenol-formaldehyde resin in Example 45 by the ecguivalent weight of the phosphites prepared in Examples 72, 73 and 74. Thus, there can be used about 2.4 grams of the resin phosphite of Example 74 with 7.2 grams of LG-56 in Formulation A with addition of 5 .2 grams of toluene dissocyanate to form a solid foamed polymer.

I claim:

1. A cigarette comprising tobacco and a filter, said filter comprising a phosphorus containing foamed polyurethane, the phosphorus being present as part of the polyurethane molecule.

2. A cigarette comprising tobacco and a filter, said filter comprising an open cell polyurethane foam made from an organic polyisocyanate and a polyhydroxy containing organic phosphite.

3. A cigarette comprising tobacco and a filter, said filter comprising an ion exchange resin and a phosphorus containing foamed polyurethane, the phosphorus being present as part of the polyurethane molecule.

4. A cigarette according to claim 3 wherein said polyurethane is made from an organic polyisocyanate and a polyhydroxy containing phosphite.

5. A cigarette comprising tobacco and a filter, said lter comprising a foamed polyurethane made from a polyisocyanate and a mixture of polyols, one of said polyols containing only carbon, hydrogen and oxygen, the other polyol being a phosphite polyol, said phosphite polyol being employed in an amount sufficient to improve the iiarne resistance of said polyurethane.

6. A cigarette comprising a rod of tobacco, a phosphorus containing foamed open cell polyurethane filter and an unfoarned phosphorus containing polyurethane slain around said foamed polyurethane, the phosphorus in each instance being part of the polyurethane molecule.

7. A cigarette according to claim 6 wherein said tobacco is surrounded by a paper wrapper, having open ends and said polyurehtane skin covers one end of said wrapper.

8. The method of purifying tobacco smoke comprising passing said smoke through a filter comprising a phos phorus containing foamed polyurethane, the phosphorus being present as part of the polyurethane molecule.

9. The method of purifying tobacco smoke comprising passing said smoke through a filter comprising an open celled foam of a polyurethane made from a polyisocyanate and a polyol containing phosphite.

References Cited in the file of this patent UNITED STATES PATENTS 2,739,598 Eirich Mar. 27, 1956 2,754,829 Hess iuly 17, 1956 2,933,460 Richter et al. U Apr. 19, 1960 3,006,346 Golding Oct. 31, 1961 FOREIGN PATENTS 1,232,795 France May 9, 19st) 834,854 Great Britain May 11, 1969 OTHER REFERENCES Bio-Rad Labratories, ion Exchange Resins and Celluloses, Price List N. Pages 6 and 7. Published October 1, 1959, by Bio-Rad Laboratories, Richmond, Calif.

Ion Exchange Resins, by Robert Kunin and Robert J. Myers. Published 1950 by John Wiley & Sons, Inc., New York, page 26.

Source Book of the New Plastics, by H. R. Simonds. Page 30, published 1961 by Reinhold Publishing Corp. 

1. A CIGARETTE COMPRISING TOBACCO AND A FILTER, SAID FILTER COMPRISING A PHOSPHORUS CONTAINING FOAMED POLYURETHANE, THE PHOSPHORUS BEING PRESENT AS PART OF THE POLYURETHANE MOLECULE. 